31978422 has 64 divisors (see below), whose sum is σ = 83865600. Its totient is φ = 8838720.

The previous prime is 31978421. The next prime is 31978447. The reversal of 31978422 is 22487913.

It is a super-2 number, since 2×31978422² = 2045238947220168, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31978421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10354 + ... + 13082.

It is an arithmetic number, because the mean of its divisors is an integer number (1310400).

Almost surely, 2^31978422 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31978422, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41932800).

31978422 is an abundant number, since it is smaller than the sum of its proper divisors (51887178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31978422 is a wasteful number, since it uses less digits than its factorization.

31978422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2778 (or 2772 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 31978422 is about 5654.9466840988. The cubic root of 31978422 is about 317.4088340565.

It can be divided in two parts, 31978 and 422, that added together give a square (32400 = 180²).

The spelling of 31978422 in words is "thirty-one million, nine hundred seventy-eight thousand, four hundred twenty-two".